I absolutely adore the nickname [name_f]Lottie[/name_f] for a little girl, but I feel the main formal name for it, [name_f]Charlotte[/name_f], is becoming too popular. Could [name_f]Lottie[/name_f] work just on its own? If anyone knows of any names to get [name_f]Lottie[/name_f] as a nickname, please comment 
I think [name_f]Lottie[/name_f] works fine on its own. Sure, people will assume [name_f]Lottie[/name_f] is short for [name_f]Charlotte[/name_f], but a simple “just [name_f]Lottie[/name_f]” would suffice.
If not, [name_f]Carlotta[/name_f] and [name_f]Liselotte[/name_f] are good ways to get to [name_f]Lottie[/name_f]. There’s also [name_f]Scarlett[/name_f] and [name_f]Violet[/name_f] if you don’t mind a stretch.
I know a girl who is just [name_f]Lottie[/name_f], so I definitely think it works on its own. In the UK, [name_f]Lottie[/name_f] actually ranks 78th, and is climbing in the ranks, so I think you’d be fine using it as a full name.
I know a [name_f]Lottie[/name_f] who has that as her full name. She’s a wonderful woman, and wears it well. [name_f]Scarlett[/name_f], [name_f]Violet[/name_f], [name_f]Colette[/name_f], [name_f]Ottilie[/name_f], [name_f]Ottiline[/name_f], and [name_f]Loretta[/name_f] all work as longer versions, too. 
A little [name_f]Ottilie[/name_f] called “[name_f]Lottie[/name_f]” would be incredibly charming!
You could get [name_f]Lottie[/name_f] from [name_f]Clothilda[/name_f].
I personally like nicknames that are similar to but not an obvious short form ([name_f]Elizabeth[/name_f]/[name_f]Ellie[/name_f], [name_f]Catherine[/name_f]/[name_f]Catie[/name_f], [name_f]Eleanor[/name_f]/[name_f]Nora[/name_f]), so I really [name_u]LOVE[/name_u] [name_f]Loretta[/name_f]. Though [name_f]Charlotte[/name_f] lends itself more easily and is more common
I adore [name_f]Lottie[/name_f], but don’t like [name_f]Charlotte[/name_f] for numerous reasons, so I have [name_f]Lieselotte[/name_f] on my own List. I also really love the suggestions [name_f]Ottilie[/name_f] and [name_f]Violet[/name_f]!
I love [name_f]Violet[/name_f], [name_f]Rosette[/name_f], and [name_f]Colette[/name_f]!
Lots of interesting suggestions so far, I think it would work with any of them. Also, there’s no rule saying that you can’t just use the nn “[name_f]Lottie[/name_f]” as a standalone first name. I like it as a fn.
If you’re open to alternatives… You also have quite a few options with “[name_f]Lettie[/name_f]”…
I would suggest considering:
[name_f]Colette[/name_f]
[name_f]Juliette[/name_f]
[name_f]Violet[/name_f] ([name_f]Violetta[/name_f])
[name_f]Nicolette[/name_f]
[name_f]Cosette[/name_f]
[name_f]Josette[/name_f]
[name_f]Mariette[/name_f]
[name_f]Ivette[/name_f]/[name_f]Yvette[/name_f]
[name_f]Fleurette[/name_f]
[name_f]Georgette[/name_f]
[name_f]Idette[/name_f]
[name_f]Laurette[/name_f]
Hazelotte
[name_f]Liselotte[/name_f]
It is not an intuitive nickname, but in “Phantom of the [name_f]Opera[/name_f]”, the main character [name_f]Christine[/name_f]'s childhood nickname is [name_f]Lottie[/name_f].
I love [name_f]Lottie[/name_f] as a nn for [name_f]Ottilie[/name_f]. Also really like the suggestion of [name_f]Violet[/name_f].
[name_f]Charlotta[/name_f] or [name_f]Carlotta[/name_f]
I think [name_f]Lottie[/name_f] could work for [name_u]Elliott[/name_u].
[name_f]Carlotta[/name_f] is a really pretty alternative to [name_f]Charlotte[/name_f] and definitely works with [name_f]Lottie[/name_f]. Same with [name_f]Clothilde[/name_f] / [name_f]Clotilde[/name_f].